New spatially explicit method for detecting extracellular protease activity in biofilms.

Area of Science:

• Microbiology
• Biochemistry
• Environmental Science

Background:

• Extracellular protease activity is crucial for biofilm development and function.
• Understanding protease localization at the biofilm-substratum interface is challenging.
• Existing methods may not provide sufficient spatial resolution.

Purpose of the Study:

• To develop and validate a novel method for detecting extracellular protease activity at the biofilm-substratum interface.
• To compare the novel method with a standard assay for detecting protease activity.
• To visualize microspatial patterns of bacterial distribution and protease activity.

Main Methods:

• A new technique utilizing fluorescent molecules bound to cellulose substrata with a lectin.
• Extracellular proteases degrade the lectin, releasing a fluorochrome.
• Combination with confocal scanning laser microscopy for visualization.

Main Results:

• The novel technique detected extracellular protease activity at the biofilm-substratum interface.
• The new method showed similar responses to N supply manipulation as a standard dissolved-substrate assay.
• Direct visualization of bacterial distribution and protease activity patterns was achieved.

Conclusions:

• The developed method is effective for detecting extracellular protease activity at the biofilm-substratum interface.
• This technique allows for visualization of enzyme activity and bacterial distribution in biofilms.
• The findings provide new insights into biofilm structure and function.